Very bad user experience, thread context lost, when someone replies to a post that is locally blocked

[jsbiff]

Steps to reproduce the problem

1. User A on a non-blocked server posts a top-level post, starting a thread
2. User B (you) reply
3. User C on a blocked server (possibly also individually blocked, not sure) replies
4. User D on a non-blocked server replies to C
5. User B gets a notification of User D's reply
6. User B clicks on notification to go to thread, but only sees User D's reply and none of the rest of the thread - User D's reply is now an orphan, broken off from the threaded discussion

Expected behaviour

I should see all posts in the thread that aren't from blocked users/servers

Actual behaviour

Only see the reply with no thread context

Detailed description

This has been increasingly happening to me lately - the local server admin is blocking a lot of problematic servers, which of course is necessary, if remote servers won't block harmful, hateful, illegal, or scam posts, then local server blocking becomes necessary.

But, I keep getting this problem where I get a notification of a reply, and I click on it, and I see a single post with no context, and I can't make any sense of the post without the context. Also, there's no meaningful way of discovering what thread it was part of the reply chain to, to go find it manually.

Understandably, Mastodon can't/shouldn't show me the blocked content that the user is replying to - but it would be a much better experience if Masto would show me all the rest of the non-blocked posts in the thread.

I suspect there might be an underlying technical challenge here, like, for example, perhaps right now the design of content blocking is such that to find the ancestor posts to the reply, Mastodon would need to have a copy of the blocked content in order to parse the metadata to find what posts the blocked content is a reply to, and maybe right now Masto never even connects to blocked servers to download blocked content.

If that's the case, perhaps that's just entirely a wrong way to solve the blocking problem? Maybe blocking should be a server-side filtering, where the server actually downloads content from the blocked server, so that it can parse the metadata to find the ancestors in the thread, but simply filters out that blocked content in the display?

Or perhaps this is a current shortcoming of ActivityPub? Like, perhaps every reply-post should include metadata indicating what the top-most (original) post for the thread was, so that at least the non-blocked replies can allow the server to find the original non-blocked post that started the thread?

Mastodon instance

universeodon.com

Mastodon version

v4.3.0-nightly.2024-05-13

Technical details

If this is happening on your own Mastodon server, please fill out those:

• Ruby version: (from ruby --version, eg. v3.1.2)
• Node.js version: (from node --version, eg. v18.16.0)